The objective of the proposed research is the genetic dissection of eye development. The principle method will be genetic analysis of various eye types that are seen in F2 segregants of cave fish x surface fish crosses. Light and electron microscopic examination will also be made of the F2 segregant types. The lens crystalline composition and distribution in the surface fish and segregants will be examined by immunoelectrophoretic and immunofluorescence methods. Transplantation of presumptive eye structures between the surface fish and F2 segregant classes will also be carried out. Similar genetic and histological analysis will also be carried out on the various types of cataracts that have recently been observed amongst segregants.